Receiver transmitter



April 29, 1947. Q N 2,419,799

RECEIVER TRANSMITTER Filed Aug. 6, 1945 2 Sheets-Sheet l as as INVENTORCARL W. SWAN April 29, 1947.

c. w. swAN 2,419,799

RECEIVER TRANSMITTER Filed Aug. 6', 1943 2 Sheets-Sheet 2 Mr-gm 03 m 11'v FIG. 4

mvemon CARL W. SWAN v ATT NEY Patented Apr. 29, 1947 RECEIVERTRANSMITTER Carl W. Swan, Skokie, IlL, assignor to Teletype Corporation,Chicago, Ill.-,- a-corporation of Delaware Application August 6, 1943,Serial No. 497,592

2 Claims.

This invention relates to telegraph apparatus and more particularly tostart-stop telegraph apparatus.

It is often desired to have code signal receiv ing apparatus whereincertain predetermined code signals may be received, where visibleindications will be given that a certain signal has been received, andwhich will then transmit a single predetermined code signal as anacknowledgment of the received signal.

The object of the present invention is to provide an apparatus which isresponsive to predetermined code signals and which transmits a singlepredetermined code signal as an acknowledgment of the received signal.

A further object of the invention is to provide indicating means whichare operable upon the receipt of an incoming signal to identify theparticular signal received.

The apparatus in general comprises a selector magnet, which uponenergization in response to received signals releases areceiver-distributor for rotation. The incoming signal permutably con--trols a plurality of code bars, which, in turn,

control a plurality of code bails. An extension on each code bailcontrols an electrical switch, to establish an electrical circuit tolight a lamp and indicate the particular code signal received. Theselector magnet also releases a transmitterdistributor for rotationwhich transmits a predetermined code signal over an associated signalingchannel to indicate that the selector mechanism has operated.

The features and advantages of the invention will become apparent fromthe following detailed description of a specific embodiment thereof,when read in conjunction with the accompanying drawings, in which:

Fig. 1 is a front elevational View, partly broken away, showing theapparatus embodying the invention;

. Fig. 2 is a sectional plan view, taken approximately on the line 2-2of Fig. 1,

Fig. .3 is a side elevational View, partly broken away, of the apparatusshown in Fig. 1;

Fig. 4 is a side sectional view, taken approximately on the line 44 ofFig. 1,

Fig. 5 is a fragmentary side sectional view taken approximately on theline 5-5 of Fig. 1;

Fig. 6 is a schematic wiring diagram showing the electrical circuit ofthe received signal indicator; I

Fig. 7 is a schematic Wiring diagram showing the electrical circuit ofthe transmitting signal acknowledger; and

Fig. 8 is, a detail view showing the construction of the clutchmechanism. v The apparatus comprises a vertical base H which may besecured to any suitable equipment, such as a panel, etc. A pair ofbearing brackets l2 and [3' are secured by means'of screws'to the baseH, on opposite sides thereof. A shaftl4-is rotatably journalled inthebearing brackets l2 and I3, extendinghorizontally almost the entireWidth of the base ll.

The shaft l 4 is composed, toward the right end, of areceiving-distributing assembly designated generally by the numeral 5,and a transmitterdistributor assembly designated generally by thenumeral ll toward the left end. The assemblies It and I! are separatedby a somewhat thinner section of shafting, around which is positioned afreely rotatable sleeve l3. The'sle'eve l8 has a gear [9 firmly securedto its left end, as seen in Fig. 1, which in turn engages with a pinion2| which is situated at the end of a shaft extending from the motor 22(Fig. 2). The motor shaft 'constantly rotates, causing the pinion 2! todo likewise, thus causing the sleeve l8 to be constantly rotated. Theshaft l4, however, is intermittently driven, the driving force beingimparted by the constantly rotating sleeve l8.by means of clutchingmechanism which will hereinafter be explained in detail. i

A bracket 23, better seen in Fig. 3, is securely fastened to the platell,and supports an electromagnet 24 which is positioned adjacent theup,- per end of an armature 26. The armature. 26 is normally positionedaway from the electro-magnet 24, by means ofa spring 21 which is securedto the upper end 'of the armature 26 and to the base II. The magnet 24is responsive to code signal impulses, preferably of the Baudot type,which are'received by the receiving apparatus over a signaling channel,as will be hereinafter explained. a

The receiver-distributor assembly 16 comprises a disc-29 and eight cams3ll to 31, inclusive, all firmly secured to the shaft I4 in such amanner as to rotate with the shaft. The cam 30 to 31, inclusive, eachhave an associated cam follower 39 to 46, respectively, which are eachshaped with a lug 56, thereon to be operated by the corresponding camduring a predetermined portion of the cycle of operation of the shaft M,the time of operation depending on the individual contour of the cams.The cam followers 39 to 46 are each pivotally mounted in a 'block 48which is secured 'to and extends from the back of the base II'. The camfollowers are normally pivoted 3 'so as to be in engagement with theirassociated cams by means of individual springs 49.

The cam follower 45 is formed at its forward end with anupwardly-extending lug 5|, and at its opposite end with an upwardlyextending member 52 which acts as a clutching and clutch release member(Fig. 8). The cam follower 45 is normally held in a downward positionasthe lower end of the armature 26 is normally above the upturned lug5|. This pivots the member 52 which is a part of the cam follower 45, ina counterclockwise direction, as viewed in Fig. 3, and

allows it to disengage the clutching mechanism, as will be explainedlater. In the event that the armature is moved from above, the upturnedlu 5|, due to the energization of the magnet 24, the cam follower 45will pivot in a clockwise direction, as viewed in Fig. 3, under thetension of the spring 49, which will result in the member '52 also beingmoved in a clockwise direction to thereby allow the clutching mechanismto engage'ahd cause rotation of the shaft [-4. The cam follower 45 isunder the control of its associated cam 35 and will only be permitted torise during a certain period of the cycle of operation of the shaft l4,even though the armature 26 may not be above the upturned lug 5 I.

' Cam followers 39, 40, 42, 44 and 46 are each formed, toward theirforward end, with a shoulder 53 and a square end 54, as better seenin 3.These cam followers are normally urged toward thecontour of'theirassociated cams 30, 3|, 33, 3,6, and 31, respectively, by means of theindif'dual springs 49, which causes engagement of the, upwardlyextending lug 56, on thecam followers, with the cam surface. During acertain portion of; the cycle of operation of shaft l4, an indentationin the contour of the cam will be presented to each lug. 56, on each camfollower which, due to the spring 49 pivoting the cam follower in aclockwise direction, as viewed in Fig.

3, willv cause the, cam followers to rise to their upper position. Theforward end of the cam followers are heldin a lateral position by meansof a pair of guide plates 51, one plate being positioned, to either sideof theindividual cam followers.

The cam follower, 4| isformeduat itsforward end in a configuration, asseen in Fig. 4, wherein theforward end is formed of two opposite,roundedlugs 58 with an. opening between. them in the shape .of. asemi-circle which has an upwardly extending lug 59, in the centerthereof. The cam-follow.er.4| is normally held with its front end in anupward position, with the armature 26' extending into the openingbetween, the lugs 58 and to one or the other side of. the upwardlyextending lug59. Thus, the lug 59 acts tov lock the armature 26 in itsforwarder-backward position. During a predetermined portion of the cycleof operation of the shaft M the cam 32, which is associated with the camfollower 4|, will; force the cam follower 4| to its downward position,overcoming the tension of the spring 49. During the interval that thecam follower 4| isinits downward position the upwardly extending lug, 59will be at a lower elevation than the} bottom of the armature 26, whichwill allow the armature to be moved to its inward or outward position,depending. on the nature of the impulses of the code signal beingreceived by theqreceiving apparatus. Thisinterval is relatively short induration and the cam immedie el i s eaiter l ws e m el o e 1, to

4 rise again due to the force of its associated spring 49, therebycausing the upwardly extending lug 59 to be positioned above theelevation of the bottom of the armature 26 and either in front or behindit. When this occurs the armature 26 will be locked in whichever of itstwo positions it happens to be in at that time, until a subsequentdownward movement of the cam follower 4|. w I

A pair of brackets 6| and 62 are secured perpendicularly to the base H,on either side of the cam followers previously described, and, in turn,support between them, toward their lower forward edge, a block 63.

Pivotally mounted on a pivot shaft 60 carried in the block 63 are aseries of selector levers 64, one, positioned in front of andcorresponding to the cam followers 39, 40, 42, 44 and 46. The selector.levers 64 are formed with a slot 66 toward their bottom, by means ofwhich they are mounted pivotally in the block 63. However, the slot islonger in length than the rod on which the levers are pivoted, so thatthere can be a limited upward and downward movement of the selectorlevers. The forward lower end of the selector levers has secured thereina spring 61 which is connected at its top to a bracket 68 which extendsoutwardly fromthe bracket 62. The springs 61 normally pivot the selectorlevers 64 in a clockwise direction, as viewed in Fig. .4, wh ch causestheir upper ends to be positioned in engagement with the square end 54of the corresponding cam, follower. The selector levers 64 are laterallyaligned with respect to their associated cam followers 39, 40, 42, 44and 46, by means of the previously mentioned pairs of guide plates 5],one of which extends on either side of a portion of the selector levers64. The upper inner edge of each of the selector levers 64 is formedwith a shoulder. 69 which may or maynot be engaged by the square end 54,of the. associated cam. follower, depending on the position of the camfollowers. The forward edge of. the selector levers 64 is formed ofthree outwardly extending lugs H spaced substantially as indicatedinFig. 4. The selector levers 64 are normally held in their upwardposition by means ofthe springs 61. In the event that the square end54of the cam followers rise to a high enough position, due to theircorresponding cam contours, the selector levers will move inwardly sothat the square end of the cam follower will rest upon the shoulder 69of each selector lever 64, Upon a subsequent counterclockwise actuationof the cam follower, due to the contourof their associated cams, theselector levers 54-wlll also be depressed, a distance limited by thelength of the slot 66 at their pivot point, because of the pressureexerted by the cam followers upon the shoulders 69.

Three code bails 12, I3, and 14 are mounted pivotally to the block 63and are urged inwardly under the tension of their individual springs 16.'These bails each have five reversible code lugs" connectedv thereto,which'may beposltioned with their body projection either above or belowthebail. Each of the lugs 11 are connected to the bail so as to bealigned with one of the selector levers 64. The code bails l2, l3, and Mhave rearwardly extending arms", 19, and 8|, respectively (Figs. 3, 4,and 5), the utility of which. will be explained later.

. Asmentioned above, there are five reversible code lugs 11 positionedon each of thecpdebails,

antic?) s a. oneeachjn' front. of eachof the five'iselector bars 6E .Thereversible code lugs are positioned .witlia' body projection extendingeither above o'ii-below the code bail, with-a leaf spring of the codelug on the opposite side of the codebail holding it in place. Thus, itis possibleto reverse the code lugs T! to a position with its bodyprojection either above or below the code bail. Depending on whether thebody projection of the code lug is above or below the code bail willdetermine whether the body projection will engage the lug H on theselector lever 64 and thus prevent the code bail from moving to itsinward limit under the force of its associated spring E6 or whether itwill enter the space between the lugs ll. The code lugs are positionedin predetermined positions so as to predetermine the code signal towhich the particular bail E2, 13, or M will be responsive; in otherwords, the position in which the bailswillmove clockwise in response topredetermined positions of the selector levers it responsive to areceived code signal.

The cam follower 43 which is under the control of the cam 35, is formedwith a depending "por- 'tion 82 which is terminated in a block havinganfadjusting screw 83 therein. Adjacent the depending portion 82 (of thecam follower '33) is a member 853 pivoted in the block :33, whichextends the width of the five selector levers 64 and which controls alever as which is also mounted pivotally in block 63. The lever 8% islaterally positioned by means of a pair of guide plates 8?, one beingpositioned on each side of the top of the lever. The front edge of thelever 88 is positioned against the code bails l2, l3, and 14, so thatwhen the lever 86 is in its forward position, the balls will not be ableto move inwardly, even though a correct setting of the selector bars haoccurred. The member 84 has an edge which, as previously mentioned,extends across the back of the five selector bars 64; this limits theinward movement of the selector bars. During a certain portion of thecycle of operation of the shaft 1 3 the cam follower GS'is presentedwith a r cess in the cam 34, which results in the cam follower beingfree to pivot in a counterclockwise direction, as viewed in Fig. 4. Whenthis occurs the depending portion 82, of the cam follower 43, likewisemoves in a counterclockwise direction allowing the member 84 to move toa limited extent in a clockwise direction, as viewed in Fig. 4. Anymovement of the member as allows the member 86 to move inwardly, underthe force exerted by the springs 16 urging the bailslZ, 13 or Minwardly, providing that a proper signal has been received. After alimited period of counterclockwise movement of the cam follower d3 itwill again be moved in a clockwise direction, as viewed in Fig. 4, dueto the contour of the surface of the cam 35. This device acts as a lockto prevent the bails from moving from an outward position except duringa limited period of the cycle of operation of the shaft l4.

Positioned below the arms '58 and '59 and adjacent the arm 8! are threeelectrical switches 88, 89 and 9!, respectively (Figs. 3, 4, andWhenever one of the bails l2, H or 14 moves in a clockwise direction, asviewed in Fig. l, its associated arms "l8, 19 or 8| will likewise movein a clockwise direction and cause pressure to be exerted upon aninsulated portion of the associated electrical switch, which in turnresults in an electrical contact being closed and an electrical circuitestablished. The electrical circuit,

. pawls 95.

as shown in :Fig. 6, includes threeelectriclights 92, 93 and 9%, whichare illuminated upon the closing of one of the electrical switches Thisacts as a visible indicator, to make it possible to readily ascertainwhich one of the balls has moved inwardly in response to thepredetermined code signal which controls it.

The clutch mechanism, as disclosed in Fig. 8, comprises three pawlsv 96which are pivotally connected to the disc 29 by means of a post 91. Thepawls 36 are normally urged in a counterclockwise direction, as viewedin Fig. 8, by means of their individual springs 98. Each of'the pawlshas a single tooth 99 thereon, the teeth being 1 positioned in astaggered relation to each other on the respective pawls, for a reasonwhich will be later explained. The disc 29 is provided with a post iii!which acts as a limit for' the clockwise movement of the pawls 98.Secured firmly to the sleeve 18 is a ratchet wheel 502 which ispositioned adjacent the three pawls 96, so that .engagement is possibleunder certain circumstances. The periphery of the disc 29 has a V-shapednotch I83 in it in which a roller 194 (Fig. l) may rest, depending onthe position of the disc 29. The roller Hi l is positioned at one end ofa lever me which is mounted pivotally to the bracket 6! and urgedagainst the periphery of the disc 29 by means of a spring 435 (Figs. 3and i) at its opposite end. In a normal position the memberbz,previously mentioned, engages the end of the pawls 95 and pivots them ina clockwise direction against the tension of their springs 98 as viewedin Fig. 8. This results in the teeth 93 of the pawls 96 being separatedfrom the teeth in the ratchet wheel I02, resulting in no rotation beingimparted from the sleeve 58 to the shaft it. Under certain conditionsthe member 52 will move in a counterclockwise direction (Fig. 8) thusfreeing the ends of the pawls 95, which in turn are urged in acounterclockwise direction under the force of their individual springs98. The teeth as will be urged toward the ratchet wheel H32 until one ofthe teeth engages the teeth on the periphery of the ratchet wheel. Thispermits rotation to be imparted to the shaft hi from the constantlyrotating shaft it. As mentioned above, the teeth 99 were positioned in astaggered relation to each other on the individual This is done so thatno matter what the position of the teeth of the ratchet wheel E02 are inrespect to the teeth lit, there will always be an immediate and positiveengagement of drive between the two members. Only one tooth will engagethe ratchet wheel. The member 52 is only held in a counterclockwiseposition for a short interval during the cycle of operation of the shaftHi and will almost immediately reassume its clockwise position. As thepawls 96 are secured to the disc 29 they will rotate with the disc andupon making a full cycle of operation of three hundred and sixty degreeswill again come in contact with the member 52, thus being moved in aclockwise direction resulting in the tooth being released from theratchet wheel. The roller I0 5, which enters the V-shaped notch I03 inthe disc 29 simultaneously with the mem ber 52 forcing the pawls Bil ina clockwise direction, acts as an anti-singing device for the clutch ingmechanism. In other words, it positively acts to cause the tooth 99 tobe disengaged from the teeth of the ratchet wheel Hi2 so that there willbe no partial engagement during the unoperative periods of the shaft l4and the .disc 29.

" A timing device is disclosed in Fig. 5 whichis utilized to hold theelectrical switch ,.9.I its ,closed position and thus insureillumination of the indicator lamp.9,4 for .a definitepredeterminedperiod of time. Connected rotatably to .I8 is an eccentric-III, whichrotates with the sleeve I8. Placed around the eccentric III, but

,free to move in respect to the eccentric, is a pawl I I2. .arm I I3against the surface of the ratchet wheel ,II by means of a springIM.Asecond pawl The pawl II2 is normally held with its H6 is securedpivotally at IIO to a portion of ,the code bail 14 so as to be able.tocmovevertically as the bail I4 rocks about pivot shaft. 60.

The upper end of the pawl III; is also normally held in engagement withthe teeth of the ratchet wheel I01, by means of the same spring H4. A

lever? is mounted loosely adjacent the block 63, so as to be pivotableunder the control of the arm 8I extending rearwardly from the code bailI I. The end H9 of the lever II! is perpendicular to the main body ofthe lever and is positioned immediately above the electrical switch 9I.A bell crank lever I2I is pivotally connected to the bracket 6| and isnormally urged in a counterclockwise direction, as viewed in Fig. 5, bymeans of a spring I22. On arm I23 of the bell crank lever I2I ispositioned adjacent the ratchet wheel I01 in such a manner that uponengagement with a post I08 the bell crank lever I2I will be moved in aclockwise direction. An

. arm I24 forms the second arm of the bell crank lever I 2I and ispositioned with its lowest end adjacent to the end H9 of the lever- Ill.The end of the arm I24 is formed witha shoulder I26 thereon, which undercertain circumstances engages the end I I9 of the lever I I! and holdsit in its depressed or counterclockwise position, as viewed in Fig. 5,thereby holding the electrical switch 9| in its closed position untilthe lever I I1 is released. The release of lever II 1 occurs when theratchet wheel I0! is stepped to a position whereat one of the posts I08will engage the arm I23 of the bell crank lever I2 I, pivoting the leverin a clockwise position against the tension of the spring I22, andthereby freeing the end II9 of the lever II! from the shoulder 126,which had previously held it downward ina latched position. The ratchetwheel I0! is moved in a step-by-step manner byrmeans of the constantly,eccentrically, moving pawl- II2 whose arm I-I3 engages the teeth on theperiphery of the ratchet wheel. Rotation of the ratchet wheel-I01 willcease when the arm ,I I3 of the pawl II2-reaches a position where theteeth are omitted, such as is designated by the numeral .109, At thispoint .the ratchet wheel will not be rotatediurther,

which acts as a pause in the timingdevice. ,However, in the event thatthe bail 14 is selectedthe pawl II6 will move upwardly and cause theratchet wheel I0'I to step one notch, which is suflicient to allow thepawl II2 to-again start the ratchet wheel I01 into step-by-steprotation. The omitted portionsv I09 of the teeth on the ratchet wheelI01 are so placedwith respect .to the posts I08 that the rotationbf theratchet wheel I01 will not stop, while the electrical contact 9I isclosed and the lamp94 is illuminated but rather,,-the omitted spaceisencountered by,

thearmI I3 justafter the post I08 has pivoted the. bell crank, lever I2I and freed tbe' lever 1 I I] from heshol ilfil IZSlwhich loqke i .d w

M riou n s o tne os 1.08 Q 'th ratchet wheel it ispossible to vary thelengthottirne which the switch 9| will be closed andthe visibleindication maintained.

.T e .tran m t i :d s uto wh c i ocate toward the left end of the shaftI4, and to; the

switches are. successively closed upon rotatlon of the shaft I 4 bymeans of their corresponding ca s. The electricalcontacts. l35 to I40,inclusive, act to suppl the impulses in a standard iiveunit transmissioncode. The switch I35 when closed ac to ansmit the start i p e, w reas te s it s 36 t 40. u ive. act to transmit the five code impulses, theproper combination of which in marking or spaeingrelation designates acertain code signal. 'As shown in Fig. 7,, the electrical switches I36and I39 have been connected to ground over an obvious circuit. Whenthese two switches are closed, by their respective cams I29 and I32,marking impulses will be transmitted. However, as electrical switchesI31, I38 and I40 are not grounded, spacing impulses will occur whentheir respective cams I30.

bymeans of any convenient type of transmittin apparatus. However, a typeof apparatus which is especially adapted forsending signals to thepresent receiver is disclosed in copending United StatesapplicationSerial No.,497,591, fi1e d on August 6, 1943, by Carl W. Swan.

A description of operation of the present unit is very similar,regardless of which one of the three possible signals is received. .Thethree code bails 12,13 and I4 correspond to the letters A, B and C, suchcorrespondence being predetermined by the position or the body proeqtionof ,the code lugs TI either above or below thebail. However, asbai1,i4 has a timing device associatedwith it, which the other twosignal bails do not have, the operation of code bail, Itwillbe.described upon receipt of ,theletterA.

The operation of the apparatus is as follows:

Contrary to the usual practice, whereinthe start impulse is normally ofspacing. nature (or no-cu rentland the stop impulse .is .of ,mar kingnature or current), the apparatus according .to the. present inventionis operable in a system ma n 24 w ich in t r c s st vtee io o th s -1 7to b oye m an the armatu .2

to be drawn toward the-magnet. j Thearmature 26 wi1l thus bemoved towardthe right, as viewed in Fig. 3, with the result that the lower end otthe armature will no longer beaboye ;the upturned-lug 5| of the camiollower 45. The cam ipllower liis ithen .Iree to pivot under thetension; or; gits essoclockwise direction.

ciated spring 49 if the low portion of the associated cam 35 ispresented to the lug 56 on the 5am follower, 45 atthat timel The camfollower will pivotfin a clockwise direction, as viewed in Fig. 3,causing member 52 to likewise move in a Such a movement of the member 52releases the pawls 96, which will then move in a counterclockwisedirection, as viewed in Fig. 8', under control of their individualsprings 98. One of the teeth 9.9 on the pawls will engage the teeth onthe ratchet wheel 32 thereby imparting rotation from the constantlyrotating sleeve l8 to the shaft l4. Upon rotation of the shaft M, thecam 36 will likewise rotate so that its low portion is no longerpresented to the cam follower 45 and which results in the cam followerbeing depressed. As the start impulse was only momentary the magnet 24has become deenergized and the armature 26, under the tension of itsspring 27, has been moved to its normal position where its lower endwill once again be positioned above the upturned lug 5! of the camfollower, and hold it down. The member 52 is likewise moved to itsbottom position so as to be in readiness to again engage the pawls 96and disengage the clutching mechanism, upon the completion of a cycle ofoperation of the shaft [4.

The cam 30 will then present its low point to the lug 56 ofthe camfollower 39, thus allowing the cam. follower to be pivoted in an upwarddirection, as viewed in Fig. 2, under the tension of itsassociatedspring 49. The cam follower 39 will be raised a distance sufiicient toallow its forward end 54 to be above the shoulder 69 of the selectorlever 64 said lever being pivoted in a clockwise direction (Fig. 4) byits associated spring 6?. Immediately thereafter the cam 30 will causethe cam follower 39 to be pivoted in a downward direction, as viewed inFig. 2, which will result in'the square end 54 of the cam follower 39engaging the shoulder 59 on the selector lever- 64 and moving the leverdownwardly, the downward movement being limited by the length of theslot 66 in the selector lever 64 at the pivot point 59. The selectorlever 54 will be held in its downward position through the entire cycleof operation of the shaft 14, as there is only one low spot on theassociated cam 30. x

The description immediately above has gone on the assumption that amarking impulse, during the first unit of the 5-unit code, has beentransmitted to the receiving unit thereby energizing the magnet 24 whichcauses the armature 26 to be attracted, as previously explained. Intheevent that a spacing or no-current impulse has been transmitted tothe receiving apparatus themagnet 24 will not be energized and thearmature 25 will remain in its normal or released position. The lowerend of the armature 26, in its normal position, is immediately above theshoulder 53 on the cam-follower 39'andthus will engage the shoulder andprevent the cam follower, from rising, under the force of its associatedspring 4.9,even though the low portion of the cam 30was presented to thelug 5-5 on the cam follower. Thus, the cam follower 39 will not be ableto rise and the selector lever- 54 will not be engaged thereby to. bemoved downwardly-by the cam follower. I

g The cam-32 has five low portions, corresponding to the number ofselector levers 64, which control the armature 25 and allow the armatureto be locked either in its attractedor in its normal released position,depending on whether a marking or a spacing impulse has beentransmitted. The

cam 32 presents a low portion to its cam follower 4|, thus allowing thecam follower 4| to rise under the force of its associated spring 49..The armature 26 will thus be locked in its marking or spacing position,by means of the lug 59 at the forward end of the cam follower ll This istoinsure that the armature 26, if moved inwardly under a markingimpulse, will not return .to its normal position on a shoulder 53 of aselector lever 64 and block the upward movement of a cam follower. Thecam follower 4| will be allowed to rise five times, once after eachimpulse has been received, thus locking the armature 26 in the positionin which it has been placed, for a short interval of the cycle ofoperation of, the shaft l4.

The above description, which has described the operation of one camfollower and its associated selector lever, is then successively carriedout to allow the other four selector levers to undergo the sameoperation. After the five impulses have been received the selectorlevers will either be in their upward position or held in their downwardposition by their associated cam followers, depending on whether aspacing or marking impulse was received. Immediately thereafter, the

cam follower 43 is presented with a low portion on its associated cam 34which allows the cam follower to move in a counterclockwise direction(Fig. 4) thus removing the pressure which its depending portion 82exerted'on the pivoted lever 84. The lever 84 will then release thepivoted lever 86, which is normally held in an outwardly position andwhich, in turn, held the bails 12, 13 and 14 in an outwardly position,thus preventing any inward movement of the bails to be causedby theirassociated individual spring 16. In the event that the code lugs Tl havebeen positioned with their body projection above the code bar,corresponding to the marking impulses of the code signal which has beenjust received, or positioned below the bail corresponding to the spacihgimpulses received, the bail will be free to move inwardly under thetension of the spring 16. For the present description we have assumedthat bail 14 has had its five code lugs Tl positioned to correspond tothe'letter A in the 5-unit Baudot code, namely two marking im-.- pulsesfollowed by three spacing impulses." Assuming this to have been thesignal received by the apparatus, the code bail M will move in:- wardlyunder the tension of its corresponding spring 16. As the bail 14 movesinwardly its arm 8| will be pivoted in a counterclockwise direction,as'viewed in Fig. 5, thereby causing the pivoted lever H! to also movein a counterclock wise direction. This will result in the end H9 of thelever H1 engaging the insulated portion of the electrical switch 9!,forcing it downwardly, and thus making an electrical co'ntactl' As shownin Fig. 6, the closing of the electrical switchSSl establishes a circuitwhich causes the light 94 to beilluminated, indicating that bail hasbeen selected and that the letter A has been received. Immediatelythereafter cam {54 causes the cam follower 43 to be moved ina clockwisedirection, as viewed in Fig. i, which results in its de-. pendingposition,82 pivotingthe lever84 inja counterclockwise. direction whichexerts pressure on the pivoted lever 85 and thus causes the bail to beforced-to its. outward position, against the tension of its spring 18.

As previously mentioned, the pivoted lever. I I! was moved in acounterclockwise direction, as

plawl Lllftvhichi iitives i n aneccentric manner m i s n t nfo lflth jntrii U imp r @Qstep yrst b mt 01 v 'a qhettwhf e l l- Th lm bhit e l; wl he m v s ne st or en eineunt' edual to the distance" between ac;-iacen te th-9n he i h y of the em et eve y ti? e the awl HZ mak s an een i r tati n l? l Meme. 1 99 a i dw l hfilp armgll fifilm fll heeu twll fin ll b? niove'djtofla pcsition where one ci it's pests will ngagethe arm 23nrt e'be11 ren1; lever j z l and caiiseit to be pivoted inalclcck wise di lefl onl. a ewe in i 7 As. t er'm. !.2 in l wg w rt hfli crank 1 31 a lever likewisebe Ii YOted in a clockwise inan nertw asing .thet nde it e ley 1 l1 tol l f ee f q he h er. 61 t {bail lll imean me ha b n et ii dhpi bi itwai d positiqn', i ts arm 8'! will noonger exert fiifes'si re On the} lever ll 1,1 which allbws sthe l efver] [1 to piv qt in a elcckvvisfe directip as viewed l t n o i s, eamtin Q t tl hou derJZB on'the bell crank, lever I2] ca'ri no longer lockit i n a 'dqwhward ppsition. HtSWeVe jdurihg h iii 'vemh the paw U hisfi filme h ai Peet wheel:- UH it d s anc ili l t t e, i tance, betweendias 'nt pgsts. nt; t j leve U1 has q l t n e'l'd ed dow w d when. w h 1f lm ele tri al i h ,haj Kl i 'elq eq' quring'thistitne end itsassdciated electfic h 4 l umina ed,

nnmeqi'eteiy aft th post I98 en es t e bell kt l j e J i t h voted i a:lei liwi'se (.111 recticn the hddk oh' the arm.;ll3 on the pawl 11 2willccme in cQntaci-, ,with a .snqfi On the periphery df the ratchetwheel Wherepn a' tobth has heen qmitted'such as is designated by the'nunieral 0,9 acts as a pause in Y the timing hi qh i m $6 tha th P?-Wl. Hni n e caius'e step' by step icta'tibn of the" ratchet heel 1- .U 'Qnets bq ed ie.inwaid m vemen er t bail wits associatedpawll I6 mov s theratchet tvhelllll pnestep'gwhichii's eh'dugh to allow the hook bn thelaifril H3 t'ciagatih irri pa rt step-by tep'..mdve rn n to the r at chetwheelnl'li'l fore distance equal td that between two adjacent posts lgtigs the timing device just described is only assgciiategl with theletter A, and its bail 14,1n0 motion will he imparted to the ratchet,wheel by e em e meriet e qew 1 hQn or C signals a re,rec ed a'nd theirrespective bails 12 en is fov army;

1 0 ntlac'ts" [3'5 t6 I40; in insive; r I ev'1euis1y -menti ned;a b 'ggnder thecbii tjcla the came in the ce t assemble n, ne'v een 1 r,., o i1y 'cdnnec'ted' seen a is sne n t me. eiee'tneei switch 135 is if thes'te'l te's'fop v r e yvwhef' sth 'o five sw ii s up, man veeires'pendt6 th' fifve' un ts in; he enae-t code. ptevipi sly rrhentidned, theseswitches may be iii'f dtsrrhineqlycon cted so as toco 'respond toanyflejsirahle lcogi'e sign'al',

as in the prese t;steneeies illustrated meme; 7. 'byth'e' lettf D. Uponthe idtaticn 12 e itf it e n? ter m lest? w llncm t e e qtl; w bheisldsesus w sive'lyg" Electrical contactjlti is closed to trans;- itQa'start signal cv'e'r, the o itgoingline; The cams to l3; 7 inclusivewi11 thenj successively close the switches I 35; to I10; inclusive,resulting 1 1 a a i m u e. in tra m tt d?! switches I 36 and B9,;whereas spacing impulses willjbe transmitted py the switches m, m andHQ, as they have notbeen grqunded arid will not establish ari electriccir ctiit 'rhqs' tlie letter will b transmitted by the present abparatlis ,over' an associated signaling 1 channel, which acts, as an ab sd' mi tb ditse i n ifi%+ t i h the ciei i's. a zwatus oi t emes? en;:imit'ha's'operated in response to an incoming signal- .t .n-

ns'pr'e'vie sly inenticned, the member 52 nee been retiir'ned td its cdtitercldckwlse positign as sen' in F1'g,;4,tn s" being: imposition toengage the'pawls 96 lipbh c'cnfifiletip'n oi aicycle cf operatidnl tifthe shaft [4 and. iivbt them in a clockwise direction, as s'eii iii Fig.8, against the tension of their esseeietea s'priiig's 98, therebyrem'o'ving their associated'teeth 39 Item the, teeth in the periphery Qfthiratgiiit whtellfl, and thus releasing the clutching mechanismsq thatn'b further rqtary iiit'iginwill be imparted to the shaft" l4 fi'bm tnefc'eiiste'nt y rotati'n'glsleeve la. until'an'othei start si'gn'a llisreceived by the ap phfatiisI thereby again settin the above de scribedmechanism into operatibn. The nner Hi4 w'il1'b'e i o'r'c'ed i'nto thnbtch M2 in the Deriph'eiy 0f' the" disc" 29 th'ei eby; positioning thedisc'in respect to the member 52st) as toinsl re that the't'qoth hasbeen completely withdrawn fr'om' the teeth of the retene wheel I02, IThe opeiaticn' cf the above a Sp'araLti s is iden tic'al' upon therege'ibt of a gene signal, with the exce t on that there is no tim ngdevice sociated with the B and Q bails 12 and '13 to act to hold theassociated lctiicaliswitches and 89 closed for a pei iod ermne and, thusilluminatethe' lights SZ 'an'd' 93 to cause the visible indicator tore'lfiain illiiminatd 61- a predetern'iinedi'rite'rvaL V y H Although aspecific mbe im'ent e: the inven-'- tion has been snewn'end desenbe 'd',it will be understood that this" mbcdh'nent is hilt illustrative and'that various lh'gdi'fication's may be made therein without departingfrom" the scope and spirit of the ihve'ritidh'.

What is claimed is; y 1. In start-step tere'g'r'epnapbai'atus, a-singleshaft, a s'elctcr magnet iespcnsive to received code signal impulses forr easi g said shaft for operation a plinfalitir 6f cc'pdeha rspperatingupqn the release of said shaft and befrndtahly selectable underthe'cqfitiol cf saidni'a'gnt, a plurality of code bails, each 0; saidcede bails rsbousiv t'ci the setting bi said cede pa e in accordeneewith a preaetenninea cbtlg'signal an elec-j tricaI ee'nmee ass'dc'iate'dwith each said code s; i e 'is i s i the ntt i said electrical eonte ttg visihly indicate the received signal, and a camfl'ist xihutoi fdrinlng part 61 said i i ehd h i i n sre i i ts ectr we:tacts'prdeterminately set to correspond to a'ciqde signal associatedtherewith said electrical con t'ac't's being under the; CQIlQIfQLO f lld j&lfi distfibiitd tq he clqs'egi "successively tq tr'anisjnit ananswjeij bacig sighal, .1, V. I electrical cgntactsjcpe atingl eeneunennwith then 'rationpijsaid odebars;

hi1 stein-ts, i1 time's shaft, a selector magnet responsive to receivedcode signal impulses for releasing said shaft for operation, a pluralityof code bars operating upon the release of said shaft and permutablyselectable under the control of said magnet, a plurality of code bails,a plurality of code lugs on each of said code bails, each of said codebails responsive to the setting of said code bars in accordance with apredetermined code signal as set by said code lugs, an arm on each ofsaid code bails, an electrical contact associated with each of said codebails, each of said electrical contacts controlled by one of said arms,means responsive under the control of said electrical contacts tovisibly indicate the received signal, and a cam distributor forming partof said shaft and having a plurality of electrical contactspredeterminately set to correspond to a code signal associatedtherewith, said electrical contacts being under the control of said camdistributor to be closed successively to transmit an answer back signal,said cam distributor and electrical contacts operating concurrently withthe operation of said code bars.

CARL W. SWAN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS 10 Number Name Date 2,266,826 Stockfeld Dec. 23,1941 1,895,718 Klenschmidt Jan. 31, 1933 1,943,475 Gurley Jan. 16, 19342,015,323 Singer Sept. 24, 1935 1 2,130,400 Salmon Sept. 20, 19382,183,022 Krum Dec. 12, 1939 2,162,170 Hicks June 13, 1939 1,698,294Potts Oct. 30, 1928 FOREIGN PATENTS 20 Number Country Date 489,531British July 28, 1938

